LED Lamp 3294-15SURC/S 400-A7 Datasheet - Brilliant Red - 2.0V - 20mA - 200mcd - English Technical Document

1. Product Overview

This datasheet provides comprehensive technical information for the 3294-15SURC/S 400-A7 LED lamp. This component is a through-hole (lamp-style) light-emitting diode designed for applications requiring reliable and robust indicator lighting with higher brightness output. The device utilizes an AlGaInP (Aluminum Gallium Indium Phosphide) chip to produce a brilliant red color with a water-clear resin lens, offering a wide viewing angle suitable for various display and indication purposes.

The core advantages of this LED include its compliance with key environmental and safety standards such as RoHS, EU REACH, and Halogen-Free requirements (Br <900 ppm, Cl <900 ppm, Br+Cl < 1500 ppm). It is available on tape and reel for automated assembly processes, enhancing manufacturing efficiency. The primary target markets for this component are consumer electronics and computing peripherals, where consistent and visible status indication is critical.

2. Technical Parameter Deep-Dive Analysis

2.1 Absolute Maximum Ratings

The Absolute Maximum Ratings define the stress limits beyond which permanent damage to the device may occur. These ratings are specified at an ambient temperature (Ta) of 25°C and must not be exceeded under any operating conditions.

• Continuous Forward Current (IF): 25 mA. This is the maximum DC current that can be continuously applied to the LED anode.
• Peak Forward Current (IFP): 60 mA. This rating applies under pulsed conditions with a duty cycle of 1/10 at 1 kHz. Exceeding this in continuous operation will degrade the LED.
• Reverse Voltage (VR): 5 V. Applying a reverse bias voltage greater than this can cause junction breakdown.
• Power Dissipation (Pd): 60 mW. This is the maximum power the package can dissipate, calculated as Forward Voltage (VF) * Forward Current (IF).
• Operating & Storage Temperature: The device can operate from -40°C to +85°C and be stored from -40°C to +100°C.
• Soldering Temperature (Tsol): The leads can withstand 260°C for 5 seconds, which is compatible with standard wave or hand soldering processes.

2.2 Electro-Optical Characteristics

The Electro-Optical Characteristics are measured at Ta=25°C with a forward current (IF) of 20 mA, which is the standard test condition. These parameters define the light output and electrical behavior of the LED.

• Luminous Intensity (Iv): 100 mcd (Min), 200 mcd (Typ). This is the measure of perceived light power emitted in a specific direction. The typical value of 200 millicandelas indicates a bright output suitable for direct viewing.
• Viewing Angle (2θ1/2): 90° (Typ). This is the full angle at which the luminous intensity is half of the intensity at 0° (on-axis). A 90° angle provides a broad viewing cone.
• Peak Wavelength (λp): 632 nm (Typ). This is the wavelength at which the spectral emission is maximum.
• Dominant Wavelength (λd): 624 nm (Typ). This is the single wavelength perceived by the human eye, defining the color as brilliant red.
• Forward Voltage (VF): 1.7V (Min), 2.0V (Typ), 2.4V (Max) at IF=20mA. This parameter is crucial for circuit design to determine the necessary current-limiting resistor value.
• Reverse Current (IR): 10 μA (Max) at VR=5V. A low reverse current indicates good junction quality.

Measurement uncertainties are provided: Luminous Intensity (±10%), Dominant Wavelength (±1.0nm), and Forward Voltage (±0.1V).

3. Binning System Explanation

The datasheet references a binning system for key parameters, indicated by codes on the packing label (CAT, HUE, REF). Binning is the process of sorting LEDs into groups based on measured performance to ensure consistency within a production batch.

• CAT (Ranks of Luminous Intensity): LEDs are sorted into bins based on their measured luminous intensity (e.g., 150-200 mcd, 200-250 mcd). This allows designers to select parts with a specific brightness range.
• HUE (Ranks of Dominant Wavelength): LEDs are binned according to their dominant wavelength, ensuring color consistency. For a brilliant red LED, bins might define specific nanometer ranges around the 624 nm typical value.
• REF (Ranks of Forward Voltage): Forward voltage is binned to group LEDs with similar Vf characteristics. This can be important for applications where consistent voltage drop across multiple LEDs in series is desired, though it is typically less critical than current regulation.

Consulting the manufacturer's detailed binning specification document is necessary to understand the exact code definitions and available ranges for the 3294-15SURC/S 400-A7.

4. Performance Curve Analysis

The datasheet includes several typical characteristic curves, which are essential for understanding device behavior under non-standard conditions.

4.1 Relative Intensity vs. Wavelength

This curve shows the spectral power distribution. For an AlGaInP red LED, expect a relatively narrow spectrum centered around 624-632 nm (dominant and peak wavelengths). The curve confirms the monochromatic nature of the output, which is ideal for color-specific indicator applications.

4.2 Directivity Pattern

The directivity (or radiation pattern) curve illustrates how light intensity varies with viewing angle. A typical pattern for a lamp-style LED with a water-clear lens shows a broad, smooth distribution, supporting the 90° viewing angle specification.

4.3 Forward Current vs. Forward Voltage (I-V Curve)

This graph shows the exponential relationship typical of a diode. The curve allows designers to estimate the Vf at currents other than the standard 20mA test condition. It is crucial for designing the driving circuit, especially for battery-powered applications where voltage headroom is limited.

4.4 Relative Intensity vs. Forward Current

This curve demonstrates the relationship between light output (relative intensity) and drive current. Light output generally increases linearly with current up to a point. Operating significantly above 20mA may yield diminishing returns and increase heat, potentially reducing lifespan.

4.5 Temperature Dependence Curves

Relative Intensity vs. Ambient Temperature: LED light output typically decreases as junction temperature increases. This curve quantifies that derating, which is critical for applications operating in high-temperature environments.
Forward Current vs. Ambient Temperature: This curve may show the relationship between permissible forward current and ambient temperature, often indicating a derating line to stay within the maximum power dissipation (Pd) limit.

5. Mechanical & Package Information

5.1 Package Dimension Drawing

The datasheet provides a detailed mechanical drawing of the LED lamp. Key dimensions include the overall diameter of the epoxy lens (typically 5mm for this style), the lead spacing (standard 2.54mm / 0.1\" for through-hole PCBs), and the total height. Notes specify that all dimensions are in millimeters, the flange height must be less than 1.5mm, and the general tolerance is ±0.25mm unless otherwise stated. The drawing also clearly indicates the anode and cathode leads, usually with the longer lead being the anode (+).

5.2 Polarity Identification

Correct polarity is essential for LED operation. The device uses the standard convention: the longer lead is the anode (positive), and the shorter lead is the cathode (negative). Additionally, there is often a flat spot on the rim of the plastic lens base near the cathode lead. The PCB footprint design must accommodate the specified lead diameter and spacing.

6. Soldering & Assembly Guidelines

Proper handling is critical to maintain LED reliability and performance.

6.1 Lead Forming

• Bend leads at a point at least 3mm from the base of the epoxy bulb to avoid stress on the internal wire bonds.
• Perform lead forming before soldering.
• Avoid stressing the package. Misaligned PCB holes causing forced insertion can degrade the epoxy resin and the LED.
• Cut leads at room temperature.

6.2 Storage

• Store at ≤30°C and ≤70% RH. Shelf life is 3 months from shipment.
• For longer storage (up to 1 year), use a sealed container with nitrogen and desiccant.
• After opening, use within 24 hours.
• Avoid rapid temperature changes in humid environments to prevent condensation.

6.3 Soldering Process

General Rule: Maintain a minimum distance of 3mm from the solder joint to the epoxy bulb.
Hand Soldering: Iron tip temperature ≤300°C (for a max 30W iron), soldering time ≤3 seconds.
Wave/Dip Soldering: Preheat ≤100°C for ≤60 seconds. Solder bath temperature ≤260°C for ≤5 seconds.
A recommended soldering temperature profile is provided, typically showing a gradual ramp-up, a stable preheat, a short time above liquidus (e.g., 260°C), and a controlled cool-down. Avoid rapid cooling. Do not apply stress to leads while hot. Re-soldering (more than one cycle) is not recommended.

6.4 Cleaning

If cleaning is necessary, use isopropyl alcohol at room temperature for no more than one minute. Do not use ultrasonic cleaning unless absolutely necessary and only after pre-qualification, as it can damage the internal structure.

6.5 Heat Management

Although the power dissipation is relatively low (60 mW max), proper heat management must be considered during design. Operating at high ambient temperatures or at high currents will increase the junction temperature, which can reduce light output (lumen depreciation) and accelerate long-term degradation. Ensuring adequate spacing on the PCB and possibly using a small heatsink on the leads can help in demanding applications.

7. Packaging & Ordering Information

7.1 Packing Specification

The LEDs are packaged to prevent electrostatic discharge (ESD) and moisture damage:
1. LEDs are placed in anti-static bags.
2. Multiple bags are packed into an inner carton.
3. Multiple inner cartons are packed into a master outside carton.
Packing Quantity: Minimum 200 to 1000 pieces per bag. Typically, 4 bags per inner carton, and 10 inner cartons per outside carton.

7.2 Label Explanation

The packaging label contains several codes:
CPN: Customer's Production Number (optional).
P/N: Production Number (the part number: 3294-15SURC/S 400-A7).
QTY: Quantity in the bag/carton.
CAT, HUE, REF: Binning codes for Luminous Intensity, Dominant Wavelength, and Forward Voltage, respectively.
LOT No: Traceable manufacturing lot number.

8. Application Suggestions

8.1 Typical Application Scenarios

As listed in the datasheet, this LED is suitable for:
TV Sets & Monitors: Power status, standby mode, or function indicators.
Telephones: Line-in-use, message waiting, or power indicators.
Computers & Peripherals: Hard drive activity, power on/off, or network status lights on routers/modems.
Its brilliant red color and good brightness make it ideal for any application requiring a clear, visible status or warning indication.

8.2 Design Considerations

• Current Limiting: Always use a series resistor to limit the forward current to the desired value (e.g., 20mA for typical brightness). Calculate the resistor value as R = (Vsupply - Vf_LED) / I_desired.
• Circuit Layout: Ensure PCB holes align perfectly with LED leads to avoid mechanical stress during insertion.
• Viewing Angle: The 90° viewing angle is suitable for front-panel indicators. For wider visibility, consider lens caps or light pipes.
• Multiple LEDs: For driving multiple LEDs, connect them in series with a higher voltage supply and a single current-limiting resistor, or connect them in parallel each with its own resistor (preferred for consistent brightness).

9. Technical Comparison & Differentiation

Compared to older technologies like GaAsP (Gallium Arsenide Phosphide) red LEDs, this AlGaInP-based LED offers significantly higher luminous efficiency, resulting in brighter output at the same drive current. The water-clear resin, as opposed to a diffused or tinted resin, provides the highest possible light extraction and a more saturated, vivid red color. Its compliance with modern environmental standards (RoHS, Halogen-Free) makes it a suitable choice for products sold in regulated markets like the EU. The robust package and detailed handling guidelines indicate a design focused on reliability in volume manufacturing.

10. Frequently Asked Questions (Based on Technical Parameters)

Q: What resistor value should I use with a 5V supply to drive this LED at 20mA?
A: Using the typical Vf of 2.0V: R = (5V - 2.0V) / 0.020A = 150 Ohms. Use the nearest standard value (e.g., 150Ω or 160Ω). Always consider the maximum Vf (2.4V) to ensure sufficient current in the worst case.

Q: Can I drive this LED directly from a microcontroller pin (3.3V or 5V)?
A: It is not recommended to connect it directly without a current-limiting resistor. A typical MCU pin can source/sink only 20-25mA, which is at the absolute maximum limit of this LED. Always use a resistor. For 3.3V logic: R ≈ (3.3V - 2.0V)/0.02A = 65Ω.

Q: The luminous intensity is 200 mcd typical. Is this bright enough for outdoor use in daylight?
A: 200 mcd is suitable for indoor indicators or close-range viewing. For direct sunlight viewability, a much higher intensity (often >1000 mcd) or a focused lens would be required.

Q: What is the difference between Peak Wavelength (632 nm) and Dominant Wavelength (624 nm)?
A: Peak Wavelength is where the physical emission spectrum is strongest. Dominant Wavelength is the single wavelength the human eye perceives, factoring in the eye's color sensitivity (photopic response). Dominant wavelength is the better metric for describing the perceived color.

11. Practical Design & Usage Case

Case: Designing a Power Indicator for a Desktop Switch Mode Power Supply (SMPS).
The SMPS outputs 5V standby power. The goal is to add a bright, reliable power-on indicator.
Implementation: Place the LED on the front panel. Connect the anode through a 150Ω current-limiting resistor to the 5V standby rail. Connect the cathode to ground. The resistor power rating needed is P = I²R = (0.02)² * 150 = 0.06W, so a standard 1/8W (0.125W) resistor is sufficient.
Considerations: Ensure the LED is mounted securely, with leads formed correctly before soldering onto the control PCB. The 90° viewing angle will provide good visibility from various angles. The brilliant red color is a universal indicator for \"power on.\" The long-term reliability outlined in the datasheet ensures the indicator will last the lifetime of the power supply unit.

12. Operating Principle Introduction

Light Emitting Diodes (LEDs) are semiconductor devices that emit light through electroluminescence. When a forward voltage is applied across the p-n junction, electrons from the n-type region and holes from the p-type region are injected into the active region. When these charge carriers (electrons and holes) recombine, they release energy in the form of photons (light). The specific wavelength (color) of the emitted light is determined by the energy bandgap of the semiconductor material used in the active region. For this device, the AlGaInP (Aluminum Gallium Indium Phosphide) material system has a bandgap corresponding to red light. The water-clear epoxy resin acts as a lens, shaping the light output and protecting the delicate semiconductor chip.

13. Technology Trends

The LED industry continues to evolve, with general trends focusing on increased efficiency (more lumens per watt), higher reliability, and lower cost. For indicator-type LEDs like the 3294 series, trends include the development of even wider viewing angles, lower forward voltages to reduce power consumption in battery devices, and enhanced compatibility with lead-free and high-temperature soldering processes required for modern PCB assembly. There is also a move towards further miniaturization in surface-mount device (SMD) packages, though through-hole lamps remain popular for prototyping, repair, and applications requiring high single-point brightness or specific mechanical mounting.